Electrical connection between electronic components is normally achieved by establishing electrically conductive pathways therebetween. Commonly, this has been done by electrically connecting the components through metallic wires extending therebetween.
More recently, however, such connections have often been established through the use of printed circuits formed on the surfaces of printed circuit boards, which boards included, essentially, a central core of non-conductive material, such as plastic, having circuit patterns of conductive material, normally copper, at one or both sides thereof. It has also been common to drill or punch holes through the sheet to allow connection with leads of other components of the circuit and to allow connections between circuits at opposite sides of the board.
Heretofore, it has been common in forming a printed circuit board to start with a single or double-clad board, i.e., a sheet of plastic material having a sheet of electrically conductive material at one or both sides of the plastic sheet, and then, by chemical processing, removing that portion of the conductive sheet or sheets not needed or wanted, with connections through the holes being commonly established by depositing conductive material on the walls forming the holes.
While such methods for forming printed circuit boards have been found to be effective, at least for preparation of some boards, these methods have not been found to be fully satisfactory in at least some respects, including, for example, relatively high tooling and/or production costs, relatively low quality product and/or production rates, the necessity for disposition of used materials when chemical processing is involved, the loss of excessive amounts of metal that must be removed to form the desired circuit patterns.